The present invention relates to the field of machines for the food industry, and, in particular, it relates to a plant for extracting puree, or juice from food products, such as food vegetables, for example fruit, or animal, which when initially fed have large size.

The invention relates, furthermore, to a plant for extracting juice and puree from food products, in particular of vegetable origin, or animal, which carries out this method.

As well known, a variety exists of types of plants for extracting juice or puree mainly from food products of vegetable origin, fruit and vegetables, but also from animal food, such as meat and fish.

Normally, the product to treat is previously softened or chopped more or less finely in a first step, for being then put in an extraction machine in a second step. The extraction machines of the prior art are essentially made up of a fixed structure that comprises an apertured sheet of cylindrical or conical shape, so-called "sieve", and by an armature with blades that rotates inside. The armature is mounted on a shaft and caused to rotate by a motor.

The chopped product, or softened, which enters extraction machine is pushed radially continuously by the blades against the sieve by centrifugal force. This way it is filtered through the holes of the sieve, producing a puree and a liquid part of the product that is conveyed for being then subject to further treatments. The solid part that cannot pass through the sieve, instead, is conveyed axially opposite to the inlet of the sieve and is automatically brought to a discharge station as a waste material. See on this argument patent No. IT1199392.

A known process of this kind, for example, is the so-called extraction at room temperature, which is carried out in two steps: a first step of softening the food pulps through a plurality of pulses in quick succession and a second step of separation of the useful part (puree or juice) from the waste solid parts, which is carried out in an extracting machine as above described.

During the softening step the pulses in quick succession are obtained by a cylindrical or conical body, or stator, which has protrusions on its inner surface, and by an armature having blades that rotates in the stator pushing by centrifugal force the food pulps against the protrusions, and generating a series of pulses that cause the softening of the food product. See on this subject matter patent n. IT1249363.

In the extraction process at room temperature, according to the state of the art above described, the steps of softening and extracting are carried out in a single compact working unit that has a single motor: the respective softening and extracting armatures are mounted on the same axis and rotate then at the same speed.

See Fig. 1 and the relative description below.

Another solution of the prior art described for example in WO2005039308 comprises, instead, two different drives, respectively one for the softening step and another for the extracting step. This solution permits to treat more or less sensitive products, which are affected by the softening step in a different way, and so to calibrate better the separation between puree and solid parts.

The vegetables from which the puree can be obtained may be fresh or frozen. Even if treating frozen products is much more expensive, because they stay more time in the production cycle than fresh products, using frozen products can be advantageous for keeping the vegetables with time, for covering long distances of transportation and for keeping at most the organoleptic qualities of the vegetables that would be quickly reduced after harvesting.

Presently, in order to extract puree and/or juice from a vegetable product loaded at a temperature lower than zero degrees or in any case completely or partially frozen many different processes can be used.

The product is normally kept at different temperature under zero in various forms and size, such as blocks, barrels, or IQF (Individually Quick Frozen). In the first cases, they are vegetables previously frozen in parallelepiped shape, or also cylindrical shape with the size of a standard barrel of 200 kg. In the IQF case the vegetable product is frozen singularly or in blocks and stored.

Being generically products that are kept frozen for many months and then put on the market, it is necessary to maintain the taste and the qualitative features as much as possible unchanged, for not to spoil products with a higher value than the fresh products.

When exiting from a cold store (temp. from -40°C to 0°C) the frozen products have a hardness assimilated to that of the ice and cannot be treated with the devices for making puree from fresh vegetables or already completely defrosted vegetables. Therefore, the product must first be completely defrosted.

Normally, the mostly used defrosting systems are those that use vapour as heat exchange fluid, even if plants are known that use the electric energy directly by means of resistances or indirectly by microwave systems or other devices that exploit electric or magnetic fields. They provide normally a conveyor belt for the product, which is of IQF type, up to a screw conveyor where a direct or indirect injection of the vapour is carried out. In the screw conveyor the product moves slowly and is subject to gradual continuous heating up to a complete defrosting. A possible softening step to assist the extraction can be carried out.

One of the major problems that is met is that a completely defrosted product, in particular of vegetable nature, deteriorates quickly and easily after defrosting. In fact, after only a few minutes from defrosting, enzymatic phenomena occur such as oxidation, that cause a change of the colour, of the consistency and of the taste of the product.

In case of frozen product the extraction plant has some limits to the production rate, mainly given to the size of the blocks of frozen product to treat. Usually, in fact, the not IQF blocks of frozen product fed to the extraction plant are larger than 300x100x500 mm. In this case the vegetable product is simply put in a plastic bag and frozen such that before freezing it forms a humid mix and by freezing it forms a large single frozen block comprising a certain number of fruit pieces, or vegetables.

Some production rate limits also exist to the extraction plants also in case of fresh product of size larger than about 130 - 150 mm, as in the case of pumpkins, watermelons, melons, etc. In fact, for treating the above described types of vegetable products, the machines should have excessive size with respect to the capacity of the production line in which they are installed.

For overcoming the above described drawbacks, presently, upstream of the machines that perform the extraction of the puree, or the juice, from the starting vegetable product, grinding machines are arranged that cut and chop the fresh product, or frozen product, into parts of reduced size and precisely from several mm to 1-2 cm. These grinding machines are designed for cutting, or chopping, the vegetable product, or frozen product, into parts of size as small as possible, since the smaller the size of the parts fed to the machines that perform the extraction, the higher the efficiency of such machines.

For the above described features, the grinding machines presently used, therefore, often cause a deterioration of the vegetable product. In fact, both in the case of fresh product having temperature between about 2°C and 5°C, and in the case of frozen product having temperature between about -40°C and 0°C, the grinding step operated by the grinding machine causes a break of the vegetable product, then freeing oxidative and pectolytic enzymes from the product before completing the extraction of the juice, or the puree, and, accordingly, jeopardizing the quality of the final product.

Another drawback of the presently known extraction plants that treat frozen vegetables, or fresh, of large size, consists of a feeding discontinuity that occurs in the extraction line owing to the presence of both of machines that are only sized for operating with substantially constant capacity, such as the extraction machines and the softening machines, and machines that work in a discontinuous way, like the machines that move bags, or barrels, of frozen product and that load the product in it contained on the conveying lines.

In WO2009/063309, in the name of the same applicant, a machine is described for extracting puree or juice from frozen food. The machine comprises an inlet duct through which the food products in the frozen status are fed. More in detail, the products enter the machine directly as IQF or, in case of frozen products, from barrels, into parts smaller previously triturated and having, for example, size set between 50 mm and 200 mm.

The frozen products that are fed to the machine enter a shredding section comprising a rotor which can rotate at a high speed in a stator, where the product is subjected to pressure pulses in quick succession by the movement of the frozen product between the rotor and the stator. This way, a shredding of the product into fragments of size less than 6 mm and a partial defrosting of the same is obtained. Then, the partially defrosted fragments are fed to an extractor to obtain a puree or juice by moving a sieve.

Also this solution has, therefore, the drawback above described and, in particular, the possibility of damaging the food product during the step of shredding the frozen product into fragments.

In FR2127299 a granulator is disclosed for obtaining granules of predetermined size range comprising two counterrotating claw-hammers and two crushing cylinders having longitudinal, meshing ribs, of triangular cross-section.

WO93/09684 described a method and a device for thawing out a frozen fruit juice in order to obtain a liquid juice by subjecting frozen blocks of fruit juice to mechanical and heating treatments. WO93/09684 furthermore described a gripper for gripping a container at a time and for moving the same from a first position to a second position arranged at the same height. At the second position the gripper tilts the container thus discharging its content in a trough positioned below the first and the second position.

It is then a feature of the invention to provide a plant for extracting puree, or fruit juice, which allows treating both fresh and frozen vegetables, of large size, i.e. of size larger than about 150 mm, without affecting the soundness of the treated vegetables and, accordingly, avoiding affecting the quality of the final product.

It is also a feature of the present invention to provide such a plant for extracting puree, or fruit juice, which allows treating both fresh and frozen vegetables, of large size, obtaining a high production rate.

It is a further feature of the present invention to provide a method for extracting puree, or fruit juice, from vegetables of large size that has the same advantages.

These and other objects are achieved by a plant according to claim 1 for extracting puree, or juice, from a partly frozen food product having predetermined size.

Other exemplary embodiments of the present invention are defined by the attached dependent claims 2 to 7.

The invention will be now shown with the following description of an exemplary embodiment thereof, exemplifying but not limitative, with reference to the attached drawings in which:

• figure 1 diagrammatically shows a perspective elevational side view of a first exemplary embodiment of a plant, according to the invention, for extracting puree, or juice, from products of vegetable origin of large size;
• figure 2 shows the plant of Fig. 1 an elevational side view thereof;
• figures 3 to 5 show an elevational side view of some possible exemplary embodiments of the plant of Fig. 1 provided by the present invention;
• figures 6 and 7 show respectively an elevational side view and an elevational front view with cross sectioned details of a first exemplary embodiment of the division means of the invention;
• figure 8 shows an elevational side view of a further exemplary embodiment of the plant of Fig. 1.

In Fig. 1 for example a plant 1 is shown, according to the invention, for cold extraction of puree, or juice, from a food product, in particular of vegetable origin, or animal. The plant 1 comprises a treating machine, for example a softening machine 20 arranged to soften a starting product obtaining a softened product through the transmission of a succession of pulses in quick succession, as described in IT1249363.

Downstream of the treating machine 20 a cold extraction machine 30 is then provided in which, in a known way and for example as described in IT1199392, but not shown in detail in the figures, advantageously a rotor is arranged that operates in combination with a sieve having a plurality of holes, in order to separate the product, in particular softened, or chopped, into a main product comprising the puree, or the juice, which crosses the sieve and is discharged through a first outlet, and into a waste material that, instead, cannot cross the sieve and is discharged through a second outlet. The treating machine, for example the softening machine 20 and the extraction machine 30, can be combined in a single machine as shown in Fig. 3, or two separate machines. In the latter case the outlet of the softening machine 20 is connected to the entrance of the extraction machine 30 by at least one connection duct; on this subject see for example Fig. 1.

According to the invention, upstream of the treating machine 20 a division machine is provided 40, in which a division means operate arranged to divide the starting food product into parts of predetermined size.

More in detail, in case of frozen food product, the division means 50' is adapted to cause the division of the frozen product 102 into parts 103 of size substantially equivalent to the single piece contained in the block, or cake, 102.

Instead, in case of fresh vegetables, i.e. preserved at a temperature set between about 2 and 4°C, a division means is provided 50 arranged to cause the division of the vegetable product 100 into parts 105 of size set between 50 mm and 130 mm, advantageously, set between 80 mm and 110 mm, for example about 100 mm, which are fed to the above described treating machine 20.

In an exemplary embodiment, the division means 50 comprises a cutting means 53 arranged to cut the food product 100, for example pumpkins, watermelons, and other pieces of food of similar size, for dividing them into a predetermined number of parts of a predetermined size, for example set between 50 mm and 130 mm.

The food products 100 can be sent to the division machine 40 by a conveyor belt 93 (Fig. 3), or a lifting conveyor belt 90 (Fig. 4), according to the position of the division machine 40 with respect to the other apparatus for the plant 1.

The cutting means 53 can comprise a certain number of knives, for example 3 cutting blades 53a, 53b and 53c, integral to a tubular support 57 mounted directly to the shaft 54 of a motor 55.

In a possible exemplary embodiment, instead, the division machine comprises a division chamber 45 in which a division means 50' operates, arranged to divide the food product, at least in part frozen, into a plurality of parts of a predetermined size. More in detail, as diagrammatically shown in Figs. 6 and 7, a block, or cake of frozen food product, in particular of vegetable origin, contains more products, for example fruit, such as strawberries, of reduced size compacted set in a block frozen product 102. In this case, the division means 50' are arranged to divide the cake, or block, of vegetable frozen product into parts of size substantially equivalent to the of a single vegetable product, for example of a single fruit, such as a strawberries 103. For example, the division means 50' may comprise, in this case, a division roller 47 arranged to rotate about a rotation axis 147 operated by a motor means 46 and equipped on the side surface with a plurality of teeth 48, in particular having curved profile.

Teeth 48 are adapted to penetrate the product, i.e. a frozen product 102, containing normally many food pieces of small size, such as strawberries, dividing it into parts 103 of a predetermined size and selected according to the type of frozen treated product. The teeth 47 are configured to penetrate the blocks, or cakes, of product at least in part frozen, avoiding in the meantime to smash them and, accordingly, to damage the single fruit pieces that, therefore, remain integer. A preferred exemplary embodiment provides that teeth 48 have a curved profile to overcome the difficulties of the grinding machines of the prior art that cut the frozen food product with sharp teeth, or smash them, damaging unavoidably the taste of the food product same.

More in detail, a predetermined number of groups can be provided, for example, four groups 48a, 48b, 48c and 48d of teeth with curved profile arranged at predetermined angular positions of the roller surface 47, in order to alternate zones 47a of the roller in which teeth 48 are provided to zones 47b of the roller without teeth 48.

In the division chamber 45, furthermore, a grid 49 can be provided having meshes of predetermined size for example substantially equivalent to that of the frozen treated product, and delimiting with a wall 44 the division chamber 45. More in detail, the presence of grid 49 is adapted to keep, in division chamber 45, the parts of product having size larger than the size of the meshes that are, then further penetrated by teeth 48. This way, it is reduced further the size of the parts of food product at least partly frozen present in the division chamber 45 up to obtaining parts of size less than the meshes that then pass go beyond grid 49.

According to the invention, furthermore, roller 47 is provided removable for being replaced with a different roller 47, in particular having teeth with curved profile 48 with different shape and distributed in a different way on its side surface. In particular, according to the type and the size of the frozen vegetable product it is possible to use a roller 47 configured to provide the division of a block into parts of size substantially corresponding to the single fruit piece.

In the exemplary embodiments shown in Figs. 1, 2, and 5, instead, the lifting conveyor means 90 is arranged between the division machine 40 and the treating machine 20. In this case, the lifting conveyor means 90 is adapted to bring the parts discharged by the division machine 40 having size set between about 50 and about 130 mm, from the height h1 to the height h2, at which the parts are put in the treating machine 20.

In a preferred exemplary embodiment, the lifting conveyor means 90 is associated with a weighing means 190, for example one or more load cells, configured to measure instantly the weight of the food, or pieces of food, which are arranged on the lifting conveyor means 90 and to generate a corresponding electric weight signal that is sent to a control means operatively connected to the motor means 47, or 56, of the division machine 40. This way, it is possible to adjust the motor means 47, or 56, and the conveyor means 90 on the basis of the electric weight signal, for feeding in a controlled and fixed way the food, or the parts of food to the treating machine 20.

If the food product is provided to the plant 1 frozen and contained in bags, or barrels 200, a loading means 120 is provided to the division machine 40 comprising a gripping means 121 of the bag, or barrel 200, sliding on a support structure 122 for bringing the bag, or barrel 200, from a gripping height hp to a discharging height hs at which the bag, or barrel 200, is tilted and its content is put in the division machine 40 through a loading mouth 41 (Fig. 1).

In a further exemplary embodiment of Fig. 2 both a loading means 120 upstream of the division machine 40 and a lifting conveyor means 90 are arranged between the division machine 40 and the treating machine 20.

In the exemplary embodiment of Fig. 5, instead, only the loading means 120 are provided upstream of the division machine 40. In this case, the layout of the plant 1 provides the division machine 40 above the treating machine 20 such that the movement of the parts of food product by the division machine 40 to the treating machine 20 is made through gravity.

The bags, or barrels 200, of frozen product can be arranged at first on a conveyor belt, for example a roller conveyor belt 130 arranged to cause the movement of the same along a conveying direction 155 and arrange, then the bags, or barrels 200 at the loading means 120.

In an exemplary embodiment, along the conveying direction 155 is arranged a preliminary heating station 230 at which a heating means is provided not shown in detail in the figure, for example a steam jet, or an electric winding heat exchanger, which is arranged to cause a first defrosting of the barrels 200 to assist the following step of discharging the food contained in the bags, or barrels 200 same in the division machine 40. More in detail, the quick defrosting made in the preliminary station 230 is adapted to detach the frozen food from the inner surface of the barrels, or bags 200.

As shown in Figs. 1 to 5, the plant 1 can comprise also a de-aeration station 110, in which de-aerating the product, and/or a station of enzymatic inactivation 140 in which, as well known, the product is heated for being brought to a temperature higher than a temperature of enzymatic inactivation. Furthermore, other machines can be provided to treat the product by further processes before its final exit from plant 1.

In an exemplary embodiment of the invention, as shown in Fig. 8, a first feeding duct 23 is provided arranged to connect the division machine 40, with the treating machine 20 and at least one second feeding duct 24 arranged to connect the treating machine 20 same with a device 250 for loading the vegetables that do not require a reduction of the size because already of a predetermined size, in particular less than 130 mm. The first and the second feeding duct 23 and 24 can be operated selectively for feeding to the treating machine 20, respectively, the parts of food product from the division machine 40, or the food as such.

The foregoing description of specific exemplary embodiments will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt in various applications the specific exemplary embodiments without further research and without parting from the invention, and, accordingly, it is meant that such adaptations and modifications will have to be considered as equivalent to the specific embodiments. The means and the materials to realise the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology that is employed herein is for the purpose of description and not of limitation.